Do you think I should bite the bullet and try a new fly wheel sensor.

So far the ecu has passed all the tests, ecu tested twice, all input values correct, but no output at wire 1 or 2.

Maybe the signal from the flywheel sensor isnt giving a strong enough reading ?

Dave

 

Couldn't you just trick the flywheel sensor into giving an output into the ECU? I mean if you know the amount of teeth, know the rotational speed, and then get a signal generator to fire some inputs into the system, wouldn't this work as a test??

Kevin

 

Dave,

I couldn't send you a spare as he used it - an interesting fact though, the car it failed in just started running rough one day and then finally ground to a halt. The flywheel sensor was still giving a measurable output, but not enough to drive the ECU. It's a (relatively) cheap part, try it and see - if it's not that, you could always sell it on Evilbay!

Barry

 

No I really think you should hook a bosch hammer up and find the problem.

Kirk

 

Barry

Thanks mate , you have already been very helpfull, maybe it is now a process of elimination with parts replacement. we all know the wires what will stop the car from firing and they are all testing ok , so the flywheel sensor logically is the next part to replace.

Kirk

I know what you are saying but things are really starting to get desperate, as the car has not run for 12 months, I cannot get access to a Bosch Hammer and is it really of any use on a non-starter.

I would love to just plug a hammer in and it say "bingo" but unless i win the lottery an Hammer is way out of my reach at the moment.

If I dont get it started soon, I think the car will sieze up.

Dave

 

Dave,

If you don't want to spend money on speculation, take the crank sensor out and post it up to me - I'll test it in my car.

Barry

 

Barry

You are amazing !!!!!!!!!!! and helpfull above and beyond the call of duty.

I will take the flywheel sensor out this weekend then decide wether to post it to you or just buy a new one, but all the same many thanks for your kind offer.



Dave

 

when you take the flywheel sensor out before you send it out look at it and see if it is clean with no residue on it, if so clean it and put back in and test it by thying to start the car again. this needs to be clean and over time it get the residue from the clutch wearing, the same as your wheels get dirty from the brakes. i know that the ecu is dependant on a strong clean signal from the sensor. i do not know that much about ocilliscopes but you might be getting a good signal but because you cannot or do not put the same load on the sensor as the system does it might show good statically but be bad under real operating conditing. you can also clean the teeth on the flywheel by having someone turn the engine by hand and access the teeth at the lower bell housing and spray it with some carb cleaner. also it might be good to inspect the the condition of the flywheel too. i was going thru my old porsche magazine and there was a good write up on this for 944. its is in 911 & porsche world number 96. he was saying he was suprised how the car was running great and then stop running at all. he was saying that there is an air gap that you must set, so check on the 964 and see if its simply dropping it in or do you need to gap it to the flywheel!!!!!!!!!!!!!!! glad you did not buy an ecu, that was close. good luck and she will be running soon.

 

i was reading and they say that the flywheel sensor is very reliable. you say you get fuel but no ignition, could this be ALARM RELATED, do you have aftermarket alarm???? does the factory alarm cut off ignition . you might want to do some more research.

 

Dutchcrunch

Thanks for the good advice, the aftermarket alarm was removed about 2 years ago and that was put on the starter and ignition wires under the dash. I have since checked all the relevent wires which were cut for the aftermarket alarm.

I assumed with power getting to the ecu the original alarm is ok.

 

you tried dme on other car it works. dme good.

you put 12 volts to pin 1 at dme connection while disconnected. you got spark at plugs. spark system good.

if you have continuity for 47 and 48 from flywheel sensor wires are good.

you verified power and ground to dme on appropriate pins, they are good.


one last thing to make sure you do not have short.... disconnect flywheel sensor, and both ignition control unit plugs ( the square electrical boxed by coils) and dme plug. check for shorts. if you have a mjultimeter put in the ohm range and if you have the feature that makes a beep when it shows a connection that will help you out. MAKE SURE DISSCONNEC THE ABOVE LISTED PLUGS SO YOU ARE CHECKING THE WIRES ONLY OR YOU WILL BE CHASING YOUR TAIL. if you test number 1,47,48 and no grounding and you have continuity then your flywheel sensor is BADDDDDDDD.


look at the flywheel sensor connector are the pins clean, pull sensor out and clean the tip, check for residue from being inside the bell housing and collecting clutch debris. if you clean connector and sensor and the wire test good. the flywheel sensor is BADDDDDD

 

This thread details how you can get the 'loaner' hammer substitute sent to you.

https://rennlist.com/forums/showthre...ferrerid=10545

Or you could buy one of the boards from ecufix and a 19 pin adapter from John Speake so you could have your own hammer

Or you could post a thread asking if one of the UK rennlisters could come over with their hammer.

I just dont see the point in wasting any more time randomly replacing parts, when 10 minutes with some diagnostics will probably locate your problem. You said it yourself. Its been 12 months.

Kirk

 

seems like this guy is disconnecting his battery and what not. i thought once you disconnect the battery you will lose the fault info stored unless its an airbag fault. in order for him to get the fault again he would have to get the car running again and have it log the fault again. i am not sure. different faults stay and some dont.

 

the reason i think it his flywheel sensor because he stated he had warning signs before the car was not starting or hard to start and that leads me to belive a component is starting to break down. if he sent voltage to pin 1 at the dme plug with it disconnected and the ignition made the plugs fire than its a problem with his flywheel sensor/ wiring. we can only go by the info that is provided. loren stated that the problem is in pin 1 and thats where he needs to check. if it has continuity and he is clearly checking correctly for grounding by taking that wire entirely out of the system and its checks out then he has to do the same with the flywheel sensor wires too. if the come out clean then its the sensor going bad. you can get a signal from the sensor but if its not up to snuff it will not work. you have to be able to clearly verify the signal voltage is within range and just not simply i see voltage. he should look and all connectors for corroision and he might get lucky and pull out flywheels sensor and clean the residue off reinstall and it might work. i know it is easy to give advice but we have all been into to deep to see clearly. even me!!!!!

 

Hey Kirk, i just read my post and i want to say first hand that i did not mean anthing personal as we are all trying to help. if he would of put the hammer to it right then and there you are right he would have it fixed by now. i just thought that one you discounect the battery like he did when he removed the dme to try in his friends car maybe that info would be lost. i will have to find that out. again did not want to insult your help in anyway. if i did i am sorry!!!!!